Exhaust-controlling valve for percussive tools.



f. wi. SLATER, EXHAUST CO'NTRLLING VALVE FOR PERCUSSWE TOCLSL APPLICATON FILEP DEC.31 1914.

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v F. M. SLATEH. EXHAUST CONTROLLING VALVE FOR ERC'USSIVE TOOLS.

APPLICATION FILED DEC.3||19I4. y

Patented Sept. 10, 1.918,

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Ihead will uncover the permitting valve the movement of the valve at l here 3 hy a portl() and passage ann port 19 being open, allowing free passage of the iluidfroin the bacl end of the cylinder The pressure exerted on the forward therefore move the piston rearwardly against the constant pressure on the smaller head 5,

the fluid from the rear end of the bore 3 eX- lhausting through passage 17, port 19, chamher 13 andport 14 to the atmosphere.l When the piston reaches a point near the end of its rearward stroke, the forward face of the port 11/7 the rearward face4 of the head 5 having previously covered the vport 8 and cut oli' the admission to the forward end of the cylinder bore 3. The opening of port 11 will permit fluid to flow past the neck 6 into the rear end ot' the bore 3. Practically coincident With the opening oi. the port 11, the forward face of the piston head 4 will uncoverthe port. 27

the exhaust of fluid from the forward end ofA the bore 3 to atmosphere through port 14. fluid from the rear end of the 'bore 3 Will .start to flow through the passage 17 and out through port 19 to atmosphere. rlhis iow .will however carry the valve 2li and 'itshead check the same time causing the head 26 to move off valve seat 22 'and open the port 20. It will he seen that at this time, sincd the port 27 is open, to the forward end ot' the cylinder `bore 3, there is no pressure on 'the face et' head-526 so that theniovenient of the'valve to the position shown in For. 3 will taire place without refais ance, this movement being accom of a very small amount or live iiuid through the port before the sal is moved, There being now pressure effi the rear faceof piston head. 4, as well as on the Vsmall head 5, the piston will 'move forwardly, the fluid in front of the piston head 4 exhausting freely thro ugh the port :20 unt-ii the piston reaches the position shown in Fig. 2, whereupon the valve 9.4; will .move to the'\position shown in Fig. 2, and the cycle oi operations above described will then. he repeated.-`

In Figs. 5 and a modified form of the invention is shown in which the pressure is constantly admitted through, the passage "Z to the rearward port-ion oiI largo cylinder here 3, fluid being alternately admitted to the rear enihof bore 2 hy a port 28 and passage 29 from the rearward end ot' bore 3 past the neck 6 near stroke of the piston, and n'iitted intermittently to the witl1 the flow in the manner oi.' a.

fluid being adforward end ci n 3l, when the piston nears theend of its forward stroke. in, this form, the passage 1"? leads te the chamber 15 romthe rearward end of the small here 2, Whileto 'take the place o? port 53" the passage leeds from a uri-- face of the piston head 4 will .its the port 19 is still open,

the end of' the rearward' recess? coveredby the piston near the end of its rearward stroke while a passage 34 leads from a port 35 near the central portion of the small here 2, which is uncovered by the piston near the end of its forward stroke, the passages 32 and 34 coinnninicating with the atmosphere through the port14.

The operation of this form is substantially the same as described with regard to the modification shown in Figs. 1 to 4, inclusive, theF difference being merely in the position of the alternately supplied portions of the cylinder. 1

Although the invention is shown in connection with a. drill in which the admission to both alternately supplied portions of the cylinder is controlled in a particular manner directly by the increment of the piston in the manner of a. so-called valveless tool, it is Suitable for tools in which the admission, is controlled in other manners by the piston, or for tools in which the adinissicn to one or both ends is controlled hy a valve mecha nism. It is, however, particularly adapted to drillsl of the type in connection with which it is herein shown, as it allows a free exhaust from. the forward end of the cylin der during the forwarf. stroke of the piston,

,permitting a heavy, uncushioned blow hy the piston, and, at the saine time, allows a free exhaust from the rearward end of the c: `in der, eliminating' aV considerable sushiwilligu effect, andsreducing the amount ot i i necessary to the rearward stroke piston,

lt is to he understood that while this present showing and description discloses certain specified modifications ot the invention, other forms and modifications are .included in the spirit and scope. of the same, as ei:- pressed in the claims.

that I claire is: l.. In a fluid operated percussivel tool, a cylinder, a piston, admission ports directly opened and closed said piston. for altermatelyv admitting motive duid to the opnosite ends of the cylinder, a. valve casing, passages constantly connecting the ends of the valve 'rising with the respective ends of the cvlindex", an exhaust port. constantly connecting the central portion. oi the valve casing with. the atmosphere, aspindle extending' longitur. nelly! ot' the valve casing, and a check valve sliding on said spindle in end oit to open and close co'niimuv the valve casing mcation alternately between the ends and thc central portion of the vaive casing.

f, ln a Huid operated permissive tool, a two diameters, a

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motive fluid against the other of said two forwardly acting surfaces, a piston controlled passage for intermittently supplying motive fluid against the surface tor driving the piston rearward, a valve easing, passages constantly connecting the ends of the valve casing with the respective ends ot' the cylinder, an exhaust port constantly connecting the central chamber of the valve casing with the atmosphere, a spindle extending longitudinally through the valve casing, and a check valve sliding on said spindle in each end ot the valve casing to open and close communication alternately between the end chambers and the central chamber ot' the valve casing.

3. Ina fluid operated percussive tool, a, cylinder, havinga bore ot' two diameters. a piston in .said cylinder having two surfaces tor driving it forward and one for driving it rea1".vard, a passage for constantly supplying motive fluid against one ot' said two forwardly acting surfaces, a piston con` trolled passage for intermittently supplying motive fluid against the other of said two forwardly acting surfaces, `a piston controlled passage for intermittently supplying motive fluid against the surface for driving the piston rearward, a valve casing having a smaller central chamber and enlarged end chambers, passages constantly connecting the enlarged end chambers ot' the valve casing wit-li the respective ends ot' the cylinder, an exhaust port constant-ly connecting the smaller central chamber of the valve casing with the atmosphere, a spindle extendiilg longitudinally through the valve casing', a 1d a check valve sliding on Said spindle in each# enlarged `end chamber of the valve casing to open and close communication alternately between the enlarged end chambers and the central chamber of the valve casing.

t. In a fluid operated percussive tool, a cylinder` a piston, admission ports directly opened and closed bysaid piston for alternately admittingr motive fluid to the opposite ends of the cylinder, a valve casing having a central chamber and end chambers, valve seats formed on the ends of said central`chani'ber, passages constantly connecting said end chambers 'of the valve casing with the respective ends of the cylinder, anl

exhaust port constantly connecting the said central chamber ot' the valve casing with the atmosphere, a check valve in each end chamber of' the valve casing, said check valve consisting of flat disks having a hollow central hub, a spindle centrally located in respect to each end chamber and passing through said central hub ot' the check valve, so that the check valve can slide on said spindle and thus advance against t'he valve seats or recede therefrom, to open 0r close conin'iunication between said end ehan'ibers and the said central chamber of the valve casing, the fiat disks being maintained far ther apart than the distance between the valve seats, so that when one disk is seated the other is held away from its seat.

In testimony whereof, I have hereunto set my hand.

FRED M. SL'IER.`

lVitnesses CLARENCE MAHN, Hanny CoBUnN. 

